Problem: If $9a + 5b + 6c = 3$ and $6x + y + 3z = 1$, what is $-50b + 24z - 60c + 8y - 90a + 48x$ ?
Solution: $= -90a - 50b - 60c + 48x + 8y + 24z$ $= (-10) \cdot (9a + 5b + 6c) + (8) \cdot (6x + y + 3z)$ $= (-10) \cdot (3) + (8) \cdot (1)$ $= -30 + 8$ $= -22$